Wind turbines have received increased attention as environmentally safe and relatively inexpensive alternative energy sources. With this growing interest, considerable efforts have been made to develop wind turbines that are reliable and efficient.
Generally, a wind turbine includes a rotor having multiple blades. The rotor is mounted to a housing or nacelle, which is positioned on top of a truss or tubular tower. Utility grade wind turbines (i.e., wind turbines designed to provide electrical power to a utility grid) can have large rotors (e.g., 30 or more meters in length) and generally have an average wind turbine rotor blade size of 24 meters to 47 meters in length (80-155 feet). In addition, the wind turbines are typically mounted on towers that are at least 60 meters in height. Blades on these rotors transform wind energy into a rotational torque or force that drives one or more generators. Wind turbine rotor blade designs have become increasingly complex to maximize aerodynamic properties and to withstand a variety of environments and conditions.
A wind turbine cannot generate electricity without the wind turbine rotor blades. Currently, if certain material failures occur in the wind turbine rotor blade, the wind turbine must be taken off-line and the wind turbine rotor blade must be replaced. The costs and time associated with transportation of replacement blades and the installation of the replacement blades is very high.
Generally, wind turbine rotor blades are fabricated from composite fiber materials and matrices, and have a twenty-year service life. Current fabrication methods used to produce wind turbine rotor blades are time and labor intensive and require special fabrication methods and facilities, as such, fabrication of wind turbine rotor blades is difficult and expensive. The process for producing wind turbine rotor blades is time and labor intensive and usually done using a hand lay-up technique to form the composite-laminate blade structure. As a result of this time and labor intensive process, any inattention to detail during the manufacturing and lay-up process to produce the wind turbine rotor blade can result in defects in the spar cap. Furthermore, the fabrication process of wind turbine rotor blades can lead to small defects in the wind turbine rotor blades that can result in increased risk of failure of the wind turbine rotor blade that results in the entire blade needing to be replaced. As such, the replacement of a blade or multiple blades on a wind turbine is an expensive endeavor.
What is needed is a wind turbine rotor blade spar cap laminate repair that is capable of being partially or fully assembled on location which reduces or eliminates transportation costs associated with turbine rotor blade replacement. What is also needed is a repair system that substantially matches the mechanical properties of the bulk of the wind turbine rotor blade, instead of replacing the entire wind turbine rotor blade once damage is found. Additional needs include, a wind turbine rotor blade spar cap laminate repair that can be applied in various blade orientations, including a horizontal position, on the ground detached from the wind turbine, or in vertical position, attached to the wind turbine rotor.